cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A210803 Triangle of coefficients of polynomials u(n,x) jointly generated with A210804; see the Formula section.

Original entry on oeis.org

1, 1, 1, 1, 3, 2, 1, 8, 10, 3, 1, 22, 37, 21, 5, 1, 63, 125, 100, 45, 8, 1, 185, 409, 410, 260, 88, 13, 1, 550, 1321, 1562, 1240, 598, 169, 21, 1, 1644, 4238, 5706, 5331, 3258, 1319, 315, 34, 1, 4925, 13534, 20284, 21507, 15651, 8071, 2776, 578, 55, 1
Offset: 1

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Author

Clark Kimberling, Mar 27 2012

Keywords

Comments

Row n starts with 1 and ends with F(n), where F=A000045 (Fibonacci numbers).
Column 1: 1,1,1,1,1,1,1,1,1,1,1,...
Column 2: A047849
Row sums: A003462
Alternating row sums: 1,0,0,0,0,0,0,0,0,...
For a discussion and guide to related arrays, see A208510.
Essentially the same triangle as (1, 0, 3, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (1, 1, -1, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938. - Philippe Deléham, Jul 11 2012

Examples

			First five rows:
1
1...1
1...3....2
1...8....10...3
1...22...37...21...5
First three polynomials u(n,x): 1, 1 + x, 1 + 3x + 2x^2.
		

Crossrefs

Programs

  • Mathematica
    u[1, x_] := 1; v[1, x_] := 1; z = 16;
    u[n_, x_] := u[n - 1, x] + (x + j)*v[n - 1, x] + c;
    d[x_] := h + x; e[x_] := p + x;
    v[n_, x_] := d[x]*u[n - 1, x] + e[x]*v[n - 1, x] + f;
    j = 0; c = 0; h = -1; p = 3; f = 0;
    Table[Expand[u[n, x]], {n, 1, z/2}]
    Table[Expand[v[n, x]], {n, 1, z/2}]
    cu = Table[CoefficientList[u[n, x], x], {n, 1, z}];
    TableForm[cu]
    Flatten[%]    (* A210803 *)
    cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
    TableForm[cv]
    Flatten[%]    (* A210804 *)
    Table[u[n, x] /. x -> 1, {n, 1, z}]   (* A047849 *)
    Table[v[n, x] /. x -> 1, {n, 1, z}]   (* A000302 *)
    Table[u[n, x] /. x -> -1, {n, 1, z}]  (* A000007 *)
    Table[v[n, x] /. x -> -1, {n, 1, z}]  (* A000007 *)

Formula

u(n,x)=u(n-1,x)+x*v(n-1,x)+1,
v(n,x)=(x-1)*u(n-1,x)+(x+3)*v(n-1,x),
where u(1,x)=1, v(1,x)=1.
T(n,k) = 4*T(n-1,k) + T(n-1,k-1) - 3*T(n-2,k) - 2*T(n-2,k-1) + T(n-2,k-2), T(1,0) = T(2,0) = T(2,1) = T(3,0) = 1, T(3,1) = 3, T(3,2) = 2, T(n,k) = 0 if k<0 or if k >= n. - Philippe Deléham, Jul 11 2012
G.f.: (-1+3*x)*x*y/(-1+4*x-3*x^2-2*x^2*y+x*y+x^2*y^2). - R. J. Mathar, Aug 12 2015